Electromagnetic relay



July 6, 1954 B- S. BENGTSSON ELECTROMAGNETIC RELAY Filed Oct.

50, 1950 fig 5 5a /7 1 a2 a5 37 20 -26 25 3, V l l 39 3nventor BE}? TILS BENGTOGON u WWW! Patented July 6, 1954 UNITED STATES PATENT OFFICE2,683,198 ELECTROMAGNE TIC RELAY Bertil S. Bengtsson,

Hartford, Conn., assignor to The Hart Manufacturing Company, Hartford,

Conn., a corporation of Connecticut Application October 30, 1950, SerialNo. 193,004

12 Claims.

The present invention relates to electromagnetic relays and, moreparticularly, to an imditions or to ments.

and the scope of be indicated in the appended claims.

In the drawings:

Fig. 1 is a side view of an assembled electromagnetic relay embodyingthe present invention;

Fig. 2 is an enlarged vertical cross sectional view of the relay shownin Fig. 1;

Fig. 3 is a fragmentary vertical cross sectional view of the relay withthe relay turned 90 degress from the position shown in Fig. 2;

Fig. 4 is a cross sectional view taken along the line 4-4 of Fig. 3;

Fig. 5 is a cross sectional view taken along the line 55 of Fig. 3; and

Fig. 6 is a cross sectional view taken along the line 6-6 of Fig. 4.

Referring to the drawings, a specific embodiment of an electromagneticrelay constructed in accordance with the invention is shown supported ona circular disclike base having a cenmay be placed about the relay, theenlarged at I5 to telescopically engage the periphery of the base l0.

Threadably received on the upper end of the boss I I and supportedthereby is a core 20 about which is disposed a coil 2i for actuating therewhich is open at its the upper end of the core 20 and surrounds thecoil 2i.

A bushing 25 having an cap [6 being 35 forms a seat for one end of a g38, the opposite end of the spring 38 being received on the upper end ofthe plunger 2! and abutting against a flange 39 thereon.

As will be apparent, the

against the bias of spring Disposed on the base I0 40 having suitablerecesses for receiving the The insulating aperture 4| to accommodate theboss H.

Disposed on a bottom surface of the insulating block 40 are a pluralityof stationary contacts 42 which are in the nature of elongated platesand are provided with downwardly extending posts 43 extending throughsuitable apertures in the base It, the posts 43 being flattened at theirlower ends to provide suitable connecting terminals. Since the specificembodiment shown in the drawing is a four-pole, doublethrow relay, thereare four stationary contacts 42 provided.

Similar stationary contacts 44 are secured to an insulating cover plate45 which extends across the top of the insulating block 40. Thestationary contacts 44 are similarly provided with downwardly extendingposts 46 which extend through apertures in the insulating block 48 andbase it, the posts 46 also being flattened at their lower extremities toprovide suitable terminals. The four upper stationary contacts 44 aredisposed in vertical alignment, respectively, with the four stationarylower contacts 42.

The movable contacts, which are adapted to be moved into engagementalternately with the upper stationary contacts 44 and the lowerstationary contacts 42, are provided by four tonguelike members whichare apertured at 5| so as to be received on posts 52 which extenddownwardly through suitable openings in the insulating block and base into provide connecting terminals. The posts 52 extend into the insulatingcover plate and are provided with a flange I 53 having a parti-sphericallower surface 54 against which the movable members may abut. The members50 are biased upwardly into seated engagement with the surface 5 3 bysprings 55 disposed about the posts 52 and engaging the base of theinsulating block 40.

The tonguelike members 59 are bifurcated at 56 to form upper and lowercontacting surfaces for engaging against the stationary contacts 44 and42, respectively. posed, of course, so that the bifurcated sections 56are situated between the upper contacts 44 and the lower contacts 42.

The bifurcated sections are engaged on generally carrier plates 59 whichare apertured at El so as to accommodate the posts 56 of the upperstationary contacts 43. Springs 62, positioned on the posts 46, urge thecarrier plates at upwardly so as to bring the members 553 in contactwith upper contacts 44 and spaced from the lower contacts :32. Thesprings 55 assist somewhat in accomplishing this normal positioning ofthe members 59. The inner ends of the carrier plates 59 are providedwith tail portions 63 which are received in a sleevelike clamp 64whereby the two carrier plates are maintained in substantial alignment.

Approximately plates 60 is a pin suitable apertures in centrally of eachof the carrier 65 extending upwardly through the insulating cover plate45 by means of which the carrier plates 66 may be actuated. As a resultof this construction, when the pins 55 are depressed downwardly, thecarrier plates 60 are likewise moved downwardly to carry the movablemembers at into engagement with the lower stationary contacts 52. Whenthe pressure on the pin 65 is removed, the springs 62 and 55 return thecarrier plates 60 and movable members 50 to the position shown in Fig. 6of the drawings, in which position the members 50 are in contact withthe upperstationary contacts 44.

The means for depressing the pins '65 comprises a yoke 10 which extendsacross the upper The members 50 are dish 56 of the members 50 triangularinsulating ends of the pins 65 through the bifurcation of the boss H.The central portion of the yoke 10 is arcuately curved to form a bearingsurface ll which may be engaged by the diaphragm 30. The center of theyoke 10 has an opening 12 through which the lower end or stud 29 of theplunger 2'! may extend to assist in positioning the yoke 10.

As will be apparent, the mounting of the yoke Til is such that the yokewill always be retained in operating position engaging the tops of thepins 65 by reason of the slot l3 of the boss H which prevents turning orlateral movement of the yoke and the lower end or stud 29 of the plunger2?, which. prevents longitudinal displacement of the yoke. At the sametime the yoke is tilta-ble about its midpoint defined by the arcuatebearing surface ll. When the solenoid of the relay is de-energized, theplunger 2'! and diaphragm 3B are thrust downwardly under the influenceof spring 38 causing the diaphragm 30 to engage upon the curved bearingsurface H of the yoke 73. This moves the yoke iii downwardly so as toactuate the carrier plates 6!} and hence the movable contact members 5icausing the members 58 to make contact with the lower stationarycontacts 42, as previously described. Inasmuch as the yoke ill may pivotabout its midpoint, it is a distinct advantage of the present inventionthat the result will be to equalize the pressure on the pins 65, thusinsuring that a full contact will be made through the agency of each ofthe triangular carrier plates 58. At the same time, the carrier plates56 may tilt at right angles to the yoke it by reason of the springsupports 62. Accordingly, the contact pressure on both sides of thecarrier plates 60 is equalized. The result is that the downward pressureexerted on the yoke ill by the diaphragm Sii will produce an equalpressure on each of the contacts of the relay, thus insuring a goodcontact at all points.

It has been found that, by constructing an electromagnetic relay inaccordance with the present invention, the amount of movement or throwrequired to actuate the switch may be reduced to as little as .0075, anda good contact will be provided at all points. Since the normal positionof the relay is maintained by a relatively heavy spring 3-8, it isunlikely that the relay can be actuated by jars or jolts to themechanism. At the same time the extremely small throw required toactuate the relay permits the relay to be actuated even though a verysmall energizing voltage and/or current is available.

The relay is formed of easily fabricated elements and may be assembledand adjusted with a minimum of diiiiculty and expense. The relay can beconstructed to withstand great extremes of temperature conditions and,in general, will function satisfactorily under extremely adverseoperating conditions.

As many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the followingclaims is intended to cover all of the generic and specific features ofthe invention herein described and all statements of the scope of theinvention which, as a matter of language, might be said to falltherebetween.

I claim as my invention:

1. In an electromagnetic relay, two pairs of spaced apart stationarycontacts having their contact surfaces in substantially the same plane,a movable contact arm disposed adjacent each of the stationary ccntactsfor movement into and out of engagement therewith, a pair of carrierplates connected, respectively, to two of said arms, spring meansforming a floating supsame, yoke having an arcuate bearing surface ingtransversely thereof and actuating means engageable with said bearingsurface.

2. In an electromagnetic relay, a pair of stationary contacts, a pair ofmovable contact arms movable simultaneously into and out of contact,respectively, with said stationary contacts, said contact arms beingprovided with bifurcated end portions, a carrier plate received in saidbifurcated end portions for positioning the movable contact arms, springmeans forming a floating support for the carrier plate, means for movingthe plate, including a member pivotally engaging the plate, actuatingmeans, and means forming a tiltable connection between said member andsaid actuating means.

3. In an electromagnetic relay, two pairs oi spaced apart stationarycontacts having their contact surfaces disposed in substantially thesame plane, a plurality of movable contact arms pivotally supported atone end and having a bifurcated free end extending, respectively, oversaid stationary contacts, a pair of carrier plates extending,respectively, into the bifurcated ends of two of said arms forpositioning same, means forming a floating support for the carrierplates, and means for moving the plates including a tiltable yokeextending between the plates and having an arcuate bearing surface, andactuating means engageable with said bearing surface.

4. In an electromagnetic relay comprising a pair of stationary contactsand a pair of movable contact arms movable simultaneously into and outof contact, respectively, with said stationary contacts, a carrier plateconnected to said arms, means forming a yieldable and tiltable supportfor the carrier plate normally maintaining the arms out of engagementwith the stationary contacts, and means for moving the plate comprisinga member having a tiltable connection with the plate, spring meansurging the member in a plate depressing direction, said member having anarcuate bearing surface extending transversely thereof, and actuatingmeans engageable with said bearing surface.

5. In an electromagnetic relay, stationary contact members, movablecontact arms movable simultaneously into and out of contact with saidsaid extendplate received in said bifurcated end portions, means forminga resilient and tiltable support for the carrier plate normallymaintaining the arms out of engagement with the stationary contacts, amovable member having a tiltable connection with said plate, means foractuating said member, and means forming a tiltable connection betweensaid member and said actuating means.

6. In an electromagnetic relay, two pairs of spaced apart stationarycontacts having their contact surfaces in substantially the same plane,

a movable contact arm disposed adjacent each the yoke and the last-namedmeans.

'2. In an electromagnetic relay, two pairs of spaced apart stationarycontacts having their contact surfaces in substantially the same plane,movable engagement therewith, a pair of carrier plates extending,respectively, into the bifurcated end portions of two of the contactarms, means forming a resilient and tiltable support for the carrierplates normally maintaining the out of engagement with the stationarycontacts, a yoke extending between the plates and operatively connectedthereto, means for actuating the yoke, and means forming a tiltableconnection between the yoke and the last-named means.

8. In an electromagnetic relay, a base, stationary lower contactssupported on the base, corresponding upper stationary contacts spacedabove the first-named stationary contacts, movable contact armsextending between pairs of stationary contacts, a carrier plateconnected to said arms, means forming a resilient and tiltable supportfor the carrier plate and normally maintaining the contact arms incontact with the upper stationary contacts, and a member having atiltable connection with said plate and having means forming a tiltableconnection with actuating means operable to depress said memher.

9. In an electromagnetic relay, tionary lower corresponding above thefirstma-nied stationary contacts,

nected to adjacent contact arms, spring means yoke.

10. In an electromagnetic relay, a base, two pairs of stationarycontacts supported on the base, two pairs of corresponding stationarycontacts supported, respectively, in substantially cated portions beingdisposed, respectively, between aiigned contacts, a pair of carrierplates extending, respectively, into the bifurcated end portions of twoof the movable contact arms, spring means forming a floating support forthe plates and urging the the contact arms with the said superposedstationary contacts, a

its ends, a diaphragm for engaging said arcuate bearing surface, springmeans urging the diaphragm against the bearing surface, and means forwithdrawing the diaphragm.

11. In an electromagnetic relay, a base, stationary lower contactssupported on the base, corresponding upper stationary contacts spacedabove the first-named stationary contacts, movable contact arms havingbifurcated end portions extending between pairs of stationary contacts,a pair of carrier plates extending into the bifurcated end portions ofadjacent contact arms, spring means forming a yieldable and tiltablesupport for the plates and normally maintaining the bifurcated endportions of the contact arms in contact with the upper stationarycontacts, a yoke extending between the plates, means forming a tiltableconnection between the plates and the ends of the yoke, a member biasedtoward the yoke for depressing the yoke and carrier plates to cause thecontact arms to move into contact with the lower stationary contacts,means forming an engagement between the member and the yoke permittingtilting movement of the yoke, and means for withdrawing the member.

12. In an electromagnetic relay, a base, stationary lower contactssupported on the base, corresponding upper stationary contacts spacedabove the first-named stationary contacts, movable contact arms havingbifurcated end portions disposed between pairs of stationary contacts, a

pair of carrier plates connected together and extending into thebifurcated end portions of adjacent contact arms, spring means yieldablyand tiltably supporting the plates and normally maintaining the contactarms in contact with the upper stationary contacts, a yoke extendingbetween the plates having a centrally disposed arcuate bearing surface,a guideway for the yoke, a diaphragm and engageable with the arcuatebearing surface of the yoke, a plunger attached to the diaphragm andspring means engaging the plunger thereby urging the diaphragm againstthe yoke.

